Line spacing mechanism



Oct. 17, 1933. AVERY 1,930,918

LINE SPACING MECHANISM Filed Jan. '7, 1932 INVENTOR HENRY A. AVERY BYE;

ATTORNEYS Patented Oct. 17, 1933 UNITED STATES LINE SPACING MECHANISM Henry Allen Avery, Groton, N. Y., assignor to L C .Smith & Corona Typewriters vInc., New York, N. Y., a corporation of New York Application January 7, 1932. Serial No. 585,281 '1 Claims. (01. 197-114).

This invention relates to improvements in line spacing mechanism for typewriting machines.

The invention provides a hand lever operated 5 pawl and ratchet mechanism for returning a platen carriage and rotating 2, platen on the carriage for line spacing the paper being typed, characterized in that rapid and violent operation of the hand lever will not operatively derange the pawl and ratchet device or cause maloperations of said device, such as insufficient or excessive rotation of the platen; and further characterized by the fact that the foregoing ends, as well as provision for setting the mechanism for varying extents of platen rotation, are attained in a mechanism of marked simplicity and few parts.

In the drawing,

Fig. 1 is a plan view showing the improved line spacing mechanism located at the left hand end of the platen carriage of a typewriting machine;

Fig. 2 is a vertical sectional view on the line 22 of Fig. 1, with the parts in normal idle position and the regulator set for rotation of the ratchet to the extent of two tooth spaces (double line space) as in Fig. 1;

Fig. 3 is a view similar to Fig. 2 showing the parts as positioned at the limit of the working swinging stroke of the hand lever made to rotate the platen and return the carriage; V

Fig. 4 is a fragmentary view showing the regulator set for single tooth (single line space) rotation of the platen with the pawl shown in normal idle position in full lines and at the limit of its working stroke in dotted lines; and

Fig. 5 is a rear view of the mechanism showing the parts positioned as in Figs. 1 and 2, the overthrow stop being omitted and certain parts being broken away in order to more clearly show other features of the mechanism.

The platen roller has its shaft 11 journalled in the two end plates of a platen carriage, the left hand end plate of which carriage is shown at 12 and has a tubular boss 13 on its inner face through which the platen shaft extends. Plate 12 is formed at its front end with two superposed lugs 14 extending outwardly or toward the left of the machine in horizontal planes, in which lugs a vertical pivot post 15 is fixedly held.

The line space hand lever is a bellcrank lever having a handle arm 16 extending forwardly in a horizontal plane from the upper end of a vertical, elongated, tubular bearing portion 17 .hand face of the ratchet wheel, together with a rotatable about pivot post 15 andem braced at its ends by lugs 14. The remainingarm of the bellcrank hand lever is a short arm 18 extending from the junction of the handle and bearing portions inward or toward the right hand side gm of the machine forward ofthe end plate and in a horizontal plane to a point approximately in the vertical plane of the line space ratchet wheel 19. Wheel 19 is located at the left hand' end of the platen roll and is held to the platen 5, to rotate with the platen. z

The hand lever is normally held rocked out. ward or to the left in the position shown in Figs. 1, 2 and 5' through the medium of a return spring 20 extendingunder the platen shaft, 7 and an adjustable stop screw 21. The stop screw is threaded horizontally through a rear-' wardly extending lug 22 on the lower end of bearing portion 1'? of'the hand lever for engagement of its inner end with the outer face of plate12, and the spring 20 is connected at its ends respectively to the outer end of the stop" screw 21 and to a stud 23 on the end plate 12. A suitable lock nut may be threadedon the stop screw against the lug 22, as shown, to insure that the stop screw will remain in adjusted position. i a

At the outer or left hand face of ratchet wheel 19 an upstanding flat sheetrnetal rockarm 24 is mounted on the platen to swing edgewise fore-and-aft of the machine about the platen axis. This rock arm is pivotally mounted on the platen at its lower end to swing about the platen axis by means of a circular bearing aperture in which fits the outwardly extending hubend 25 of the ratchet wheel, with the inner face of the rock arm held abutted against the outer or left hand face of the ratchet wheel by the inner end of the platen shaft bearing boss 13 formed on plate 12, the hub end 25 and the bearing aperture in arm 24 being of smaller diameter than boss 13, as shown in Figs. 2, 3

and 5. r I

This pivotal mounting of arm 24 at the left pendent guide finger 26 on the upper end of said arm which engages the opposite or right hand face of the ratchet wheel, effectually prevents tilting of the arm in any direction except about its pivot in a single vertical plane parallel with the vertical plane of the ratchet Wheel from any cause, and especially under thrusts and pulls of an operating link 27 which extends fore-and-aft of the machine. and connects the inner or right hand end of hand lever arm.18

in the lower end of arm 36.

to rock arm 24 at a point between the axis and the upper end of the rock arm. Link 27 is a sheet metal link so twisted or bent that its front end lies flatwise in a horizontal plane and is pivotally held to the right hand end of lever arm 18 by a vertical pivot 28, while its rear end lies flatwise in a vertical plane andis pivotally connected by a horizontal pivot 29 to rock arm 24 at the left hand face of that rock arm.

Arm 24 is a pawl carrier or support for the line space pawl 30 which lies in the vertical plane of the ratchet wheel and above the said wheel and is pivotally held at its forward end to the upper end of arm 24 by a horizontal pivot 31. with a pendent nose 32 engageable between the teeth of the ratchet wheel. The rear end of said pawl also carries a stud 33 from which a spring 34 extends downward to a lug 35 on the rear edge of arm 24 and is under tension to pull the pawl 'nose into the toothed edge of the ratchet wheel.

To permit reverse rotation of the platen and to make provision for varying the number of tooth spaces the ratchet wheel is rotated by a single operation of the handlever, the nose .of the pawl is normally held up out of engagement with the ratchet wheel by means of a sheet metal rock arm or pivoted line space regulator lever 36 pivoted at its lower end on bearing boss 13 to turn on the periphery of said boss which extends through a circular aperture finger piece 37 at its upper end extending out over the top of plate 12 and also over a latch plate 38 held by a pair of screws to plate 12 at the outer face of the plate 12 near the upper edge of plate 12.

Plate 38 has a fore-and-aft extending slot 39 the left hand edge wall of which has a notch therein at each end of the slot. Finger piece 37 has a depending latch lug 40 extending down through slot 39 for engagement in either one of said notches to hold the regulator rock arm 36 in either of two adjusted positions, one of which is shown in Figs. 1, 2, 3 and 5 and the other in Fig. 4. Arm 36 is resilient and its upper portion is bowed to form a spring constantly press: ing latch lug 40 against the notched left hand wall of slot 39. A guiding and retaining pin 41 held to regulator arm 36 works in a slot 42 in plate 12, this pin having a head at its outer end engaging the outer or left hand face of plate 12. Arm 36 has a pawl controlling lug or cam portion 43 on the edge of which stud 33 of the pawl is normally supported with the pawl nose 32 lifted out of the ratchet teeth.

A stop 44 adjustable along a slot 45 in plate 12 and clamped to said plate in adjusted position by means of a nut 46 on said stud at the outer face of the plate and a collar 47 on said stud at the inner face of said plate is engageable by the top edge of pawl 30 to limit the pivotal swing of the hand lever 1617-l8 on its working stroke, and also to jam the pawl between two teeth of the ratchet to prevent over-rotation of the platen when the hand lever is violently operated. The usual detent for the ratchet wheel is also provided, said detent comprising an arm 48 pivoted at its rear end on plate 12 at 49 and having a roller 50 joumalled on its forward end, which roller is constantly pressed against the toothed edge of the ratchet At its rear end pawl 30 is formed- Arm 36 has a wheel by a spring 51 anchored to plate 12 at 52 and to arm 48 at 53.

With the regulator 36. pulled forward and latched as in Figs. 1 and 2, stud 33 on pawl 30 is close to the rear edge of cam 43 and drops immediately into the ratchet wheel when the handle lever 16 is started .on its working stroke so that the pawl rotates the wheel practically throughout the full swinging stroke of handle arm 16 toward the right. When pawl 30 is jammed against stud 44 as shown in Fig. 3 rotation of the ratchet by the pawl and by momentum is prevented with the platen rotated a double line space, and this stud 44 takes the continued thrust of the hand lever required to return the platen carriage for the beginning of the typing of the new line of writing. If the regulator 36 is pushed rearward and latched as in Fig. 4, a corresponding operation of handle 16 will have the same result, except that the platenwill turn only a single line space by reason of the fact that stud 33 must ride along cam 43 for a greater distance during the first part of the turning movement of the hand lever 16 about pivot 15 before the pawl 30 can drop into engagement with the ratchet wheel.

What I claim is: V 1. In a line spacing mechanism, a rotatable platen roller having a shaft, a platen support having a tubular bearing boss adjacent one end of the platen roller through which said shaft extends, a line space ratchet wheel held at said end of the platen roller to turn together with the roller, 2. rock arm rockable about the platen shaft and held against the outer face of the ratchet wheel by the adjacent end of said tubular bearing boss, said rock arm extending radially beyond the periphery of the ratchet wheel and carrying a rigidguiding member contacting the inner face of said ratchet wheel adjacent the periphery of the wheel, a line space pawl pivotally held to the outer end of said rock arm, a hand lever pivoted on the platen support, and a link connecting said hand lever and said rock arm. a

2. In a line spacing mechanism, a rotatable platen roller having a shaft, a platen support having a tubular bearing boss adjacent one end of the platen roller through which said shaft extends, a line space ratchet wheel held at said 125 end of the platen roller to turn together with the roller, a rock arm rockable' about the platen shaft and held against the outer face of the ratchet wheel by the adjacent, end of said-tubu- I lar bearing boss, said rock arm extending radially 130 beyond the periphery of the ratchet wheel and carrying a rigid guiding member contacting the inner face of said ratchet wheel adjacent the periphery of the wheel, a line space pawl pivotally held to the outer end of said rock arm, a spring connecting said pawl and rock arm for swinging the pawl into the tooth spaces of the ratchet wheel, a bellcrank'hand leverpivoted on the platen support to swing about an axis perpendicular to the platen axis and having a handle arm extending transversely of the platen and lever axes and a second arm extending longitudinally of the platen axis, a link extending transversely of theplatenaxis and connecting the rock arm and said second arm'of the hand 45 lever, a line space regulator lever pivoted on said bearing boss to rock thereaboutand having a cam portion engageable by the pawl to lift and hold the pawl out of engagement with the ratchet wheel, and means onthe platen support 0 for holding said regulator in different rockably adjusted positions for varying the extent of the portion of the hand lever stroke during which the pawl is held out of engagement with the wheel.

3. In a line spacing mechanism, a rotatably mounted platen roller, a line space ratchet wheel held to turn with the roller and having a toothed peripheral edge and a hub, a rock arm journalled on said wheel hub, means holding said arm against the adjacent face of said wheel, said arm having a portion extending around the toothed periphery of the wheel and bearing against the opposite face of the wheel at a point adjacent said wheel periphery, a line space pawl pivoted on the outer end of said rock arm, a spring connecting said pawl and rock arm to swing the pawl into the tooth spaces of the ratchet wheel, and manually operable means for rocking said rock arm on said wheel hub to cause said pawl to rotate the ratchet wheel and platen roller.

4. In a line spacing mechanism, a rotatably mounted platen roller, a line space ratchet wheel held to turn with the roller and having a toothed peripheral edge and a hub, a rock arm journalled on said wheel hub, means holding said arm against the adjacent face of saidwheel, said arm having a portion extending around the toothed periphery of the wheel and bearing against the opposite face of the wheel at a point adjacent said wheel periphery, a line space pawl pivoted on the outer end of said rock arm, a spring connecting said pawl and rock arm to swing the pawl into the tooth spaces of the ratchet wheel, manually operable means for rocking said rock arm on said wheel hub to cause said pawl to rotate the ratchet wheel and platen roller, and a stop supported for jamming of the pawl on the working stroke of the pawl between said stop and the toothed periphery of the wheel to prevent overthrow of the ratchet wheel.

5. In a line spacing mechanism for typewriting machines, the combination of a platen roller having a shaft, a platen carriage having an end plate through which saidshaft extends and provided with a fixed tubular bearing for said shaft extending inward from the plate toward the adjacent end of said roller, a ratchet wheel held to turn with said roller and shaft between said bearing and the platen roller and having a cylindrical hub portion encircling said shaft and extending outward to the inner end of said bearing, said bearing having an outside diameter greater than that of said hub portion, a rock arm journalled at one end on said hub portion and corresponding in thickness substantially with the length of said hub portion, a finger rigid with said arm and carried thereby adjacent its opposite end to overhang the periphery of said ratchet wheel and loosely engage the inner face of said wheel adjacent the wheel periphery, a pawl pivotally held to said rock arm to engage the teeth of said wheel to line space the platen roller, and means for rocking said arm to actuate said pawl.

6. 111 a line spacing mechanism for typewriting machines, the combination of a platen roller having a shaft, a platen carriage having an end plate through which said shaft extends and provided with a fixed tubular bearing for said shaft extending inward from the plate toward the adjacent end of said roller, a ratchet wheel held to turn with said roller and shaft between said bearing and the platen roller and having a cylindrical hub portion encircling said shaft and extending outward to the inner end of said bearing, said bearing having an outside diameter greater than that of said hub portion, a rock arm journalled at one end on said hub portion and corresponding in thickness substantially with the length of said hub portion, a finger rigid with said arm and carried thereby adjacent its opposite end to overhang the periphery of said ratchet wheel and loosely engage the inner face of said wheel adjacent the wheel periphery, a pawl pivotally held to said rock arm to engage the teeth of said wheel to line space the platen roller, means for rocking said arm to actuate said pawl to rotate said wheel, means for restoring said arm rocking means to a predetermined normal position, and a pivotally ad-. justable line-space-regulating arm journalled at one end on saidtubular bearing at the inner face of said end plate and carrying a guide member slidably, engaging the outer face of said plate, said regulating arm having a cam portion coactive with said pawl to lift and hold the pawl out of engagement with the ratchet wheel at different points in the return stroke of the pawl in different pivotally adjusted positions of said regulating arm.

7. In a line spacing mechanism, the combination of a rotatably supported platen shaft, a platen roller and a ratchet wheel rotatable with said shaft, a support adjacent the ratchet wheel in which said shaft is journalled, a pair of rock arms each supported adjacent one end to rock about said shaft and both located between the ratchet wheel and said support, a pawl pivoted on the rock arm located nearest the ratchet wheel forrotating the ratchet wheel, means for holding the other arm in different pivotally adjusted positions, means on the latter arm engageable by the pawl to move and hold the pawl out of engagement with the ratchet wheel at points in the idle stroke of the pawl determined by the adjusted position of said arm, guide means on said adjustable arm slidably engaged with said support at the face of said support opposite that at whichsaid arm is pivoted, guide means on the pawl-carrying arm for slidably engaging the face of the ratchet wheel opposite that at which said arm is pivoted, and actuating means for vibrating the pawl carrying arm on its pivot to rotate the ratchet wheel and return said arm to a normal idle position.

HENRY A. AVERY. 

